Field of the Invention
Description of Related Art
The invention relates to the use of substituted dihydrooxindolylsulfonamides or salts thereof for enhancing the stress tolerance in plants to abiotic stress, and for enhancing plant growth and/or for increasing plant yield.
It is known that certain arylsulfonamides, for example 2-cyanobenzenesulfonamides, have insecticidal properties (cf., for example, EP0033984 and WO2005035486, WO2006056433, WO2007060220). 2-Cyanobenzenesulfonamides with particular heterocyclic substituents are described in EP2065370. Furthermore, it is known that certain aryl- and heteroaryl-substituted sulfonamides can be used as active compounds for abiotic plant stress (cf. WO2011113861). The action of certain aryl-, heteroaryl- and benzylsulfonamidocarboxylic acids, -carboxylic esters, -carboxamides and -carbonitriles against abiotic plant stress is described in WO 2012089721 and WO 2012089722.
The preparation of sulfamidoalkanecarboxylic acids and sulfamidoalkanecarbonitriles is described in DE847006. The use of selected arylsulfonamides having alkylcarboxyl substituents as growth regulators especially for limiting the longitudinal growth of rice and wheat plants with the aim of minimizing weather-related lodging is described in DE2544859, whereas the fungicidal action of certain N-cyanoalkylsulfonamides is described in EP176327. Furthermore, it is known that substituted N-sulfonylaminoacetonitriles can be used for controlling parasites in warm-blooded animals (cf. WO2004000798).
It is also known that substituted arylsulfonamides (cf., for example, WO2009105774, WO2006124875, WO96/36595) and substituted hetarylsulfonamides (cf. WO2009113600, WO2007122219) can be used as pharmaceutically active compounds. WO2003007931 likewise describes the pharmaceutical use of substituted naphthylsulfonamides, while Eur. J. Med. 2010, 45, 1760 describes naphthylsulfonyl-substituted glutaminamides and their antitumor action. Furthermore, it is known that pyrrolidinyl-substituted arylsulfonamides can be used as cathepsin C inhibitors in the treatment of respiratory disorders (WO2009026197) or as antiinfective agents in the treatment of hepatitis C (WO2007092588). The pharmaceutical use of N-arylsulfonyl derivatives of various other amino acids, for example as urokinase inhibitors (cf. WO200005214), as active compounds for the treatment of diabetes (cf. WO2003091211), as analgesics (cf. WO2008131947) and as γ-secretase modulators (cf. WO2010108067) has also been described.
The preparation of certain N-methyl-substituted dihydrooxindolylsulfonamides is described, for example, in DE2159362 and J. Chem. Soc. C (1971), 952-955, whereas ACS Combinatorial Science (2012), 14, 218 describes the preparation of spiro-pyrrolidinonyl-substituted dihydrooxindolylsulfonamides. It is also known that certain substituted oxindolyl derivatives such as, for example, pyrrolobenzimidazolones, can be used as pharmaceutically active compounds, for example as antiproliferative substances (cf. EP1598353), as CB2 agonists (cf. WO2010077839) or as active compounds with antiarrhythmic and cardiotonic action (cf. EPO431943). EP1598353 teaches synthesis routes for preparing substituted aminodihydrooxindoles. Furthermore, it is known that oxotetrahydroquinolinylsulfonamides can be used as Rho kinase inhibitors (cf. Eur. J. Med. Chem. 2008, 43, 1730).
It is known that plants can react with specific or unspecific defense mechanisms to natural stress conditions, for example cold, heat, drought stress (stress caused by aridity and/or lack of water), injury, pathogenic attack (viruses, bacteria, fungi, insects) etc., but also to herbicides [Pflanzenbiochemie [Plant Biochemistry], p. 393-462, Spektrum Akademischer Verlag, Heidelberg, Berlin, Oxford, Hans W. Heldt, 1996; Biochemistry and Molecular Biology of Plants, p. 1102-1203, American Society of Plant Physiologists, Rockville, Md., eds. Buchanan, Gruissem, Jones, 2000].
Numerous proteins in plants, and the genes that code for them, which are involved in defense reactions to abiotic stress (for example cold, heat, drought, salt, flooding) are known. Some of these form part of signal transduction chains (e.g. transcription factors, kinases, phosphatases) or cause a physiological response of the plant cell (e.g. ion transport, detoxification of reactive oxygen species). The signaling chain genes of the abiotic stress reaction include inter alia transcription factors of the DREB and CBF classes (Jaglo-Ottosen et al., 1998, Science 280: 104-106). Phosphatases of the ATPK and MP2C type are involved in the reaction to salt stress. In addition, in the event of salt stress, the biosynthesis of osmolytes such as proline or sucrose is frequently activated. This involves, for example, sucrose synthase and proline transporters (Hasegawa et al., 2000, Annu Rev Plant Physiol Plant Mol Biol 51: 463-499). The stress defense of the plants to cold and drought uses some of the same molecular mechanisms. There is a known accumulation of what are called late embryogenesis abundant proteins (LEA proteins), which include the dehydrins as an important class (Ingram and Bartels, 1996, Annu Rev Plant Physiol Plant Mol Biol 47: 277-403, Close, 1997, Physiol Plant 100: 291-296). These are chaperones which stabilize vesicles, proteins and membrane structures in stressed plants (Bray, 1993, Plant Physiol 103: 1035-1040). In addition, there is frequently induction of aldehyde dehydrogenases, which detoxify the reactive oxygen species (ROS) which form in the event of oxidative stress (Kirch et al., 2005, Plant Mol Biol 57: 315-332). Heat shock factors (HSF) and heat shock proteins (HSP) are activated in the event of heat stress and play a similar role here as chaperones to that of dehydrins in the event of cold and drought stress (Yu et al., 2005, Mol Cells 19: 328-333).
A number of signaling substances which are endogenous to plants and are involved in stress tolerance or pathogenic defense are already known. Mention should be made here, for example, of salicylic acid, benzoic acid, jasmonic acid or ethylene [Biochemistry and Molecular Biology of Plants, p. 850-929, American Society of Plant Physiologists, Rockville, Md., eds. Buchanan, Gruissem, Jones, 2000]. Some of these substances or the stable synthetic derivatives and derived structures thereof are also effective on external application to plants or in seed dressing, and activate defense reactions which cause elevated stress tolerance or pathogen tolerance of the plant [Sembdner, and Parthier, 1993, Ann. Rev. Plant Physiol. Plant Mol. Biol. 44: 569-589].
It is also known that chemical substances can increase the tolerance of plants to abiotic stress. Such substances are applied either by seed dressing, by leaf spraying or by soil treatment. For instance, an increase in the abiotic stress tolerance of crop plants by treatment with elicitors of systemic acquired resistance (SAR) or abscisic acid derivatives is described (Schading and Wei, WO200028055; Abrams and Gusta, U.S. Pat. No. 5,201,931, Abrams et al., WO97/23441, Churchill et al., 1998, Plant Growth Regul 25: 35-45). In addition, effects of growth regulators on the stress tolerance of crop plants have been described (Morrison and Andrews, 1992, J Plant Growth Regul 11: 113-117, RD-259027). In this context, it is likewise known that a growth-regulating naphthylsulfonamide (4-bromo-N-(pyridin-2-ylmethyl)naphthalene-1-sulfonamide) influences the germination of plant seeds in the same way as abscisic acid (Park et al. Science 2009, 324, 1068-1071). Furthermore, in biochemical receptor tests a naphthylsulfamidocarboxylic acid (N-[(4-bromo-1-naphthyl)sulfonyl]-5-methoxynorvaline) shows a mode of action comparable to 4-bromo-N-(pyridin-2-ylmethyl)naphthalene-1-sulfonamide (Melcher et al. Nature Structural & Molecular Biology 2010, 17, 1102-1108). It is also known that a further naphthylsulfonamide, N-(6-aminohexyl)-5-chloronaphthalene-1-sulfonamide, influences the calcium level in plants which have been exposed to cold shock (Cholewa et al. Can. J. Botany 1997, 75, 375-382).
Similar effects are also observed on application of fungicides, especially from the group of the strobilurins or of the succinate dehydrogenase inhibitors, and are frequently also accompanied by an increase in yield (Draber et al., DE3534948, Bartlett et al., 2002, Pest Manag Sci 60: 309). It is likewise known that the herbicide glyphosate in low dosage stimulates the growth of some plant species (Cedergreen, Env. Pollution 2008, 156, 1099).
In the event of osmotic stress, a protective effect has been observed as a result of application of osmolytes, for example glycine betaine or the biochemical precursors thereof, e.g. choline derivatives (Chen et al., 2000, Plant Cell Environ 23: 609-618, Bergmann et al., DE4103253). The effect of antioxidants, for example naphthols and xanthines, for increasing abiotic stress tolerance in plants has also already been described (Bergmann et al., DD277832, Bergmann et al., DD277835). However, the molecular causes of the antistress action of these substances are largely unknown.
It is additionally known that the tolerance of plants to abiotic stress can be increased by a modification of the activity of endogenous poly-ADP-ribose polymerases (PARP) or poly-(ADP-ribose) glycohydrolases (PARG) (de Block et al., The Plant Journal, 2004, 41, 95; Levine et al., FEBS Lett. 1998, 440, 1; WO0004173; WO04090140).
It is thus known that plants possess several endogenous reaction mechanisms which can bring about an effective defense against a wide variety of different harmful organisms and/or natural abiotic stress. Since the ecologic and economic demands on modern plant treatment compositions are increasing constantly, for example with respect to their toxicity, selectivity, application rate, formation of residues and favorable manufacture, there is a constant need to develop novel plant treatment compositions which have advantages over those known, at least in some areas.